sizeTracker.mjs

import { readFileSync } from 'node:fs';
import { watch } from 'node:fs/promises';
import path from 'node:path';
import { styleText, parseArgs } from 'node:util';
import { compileSync } from './tasks/compile.js';

const ac = new AbortController();
const { signal } = ac;

// const initialSize = 10403;

function getSize() {
  const { code } = compileSync();
  return code.length;
}

function humanReadableSize(size) {
  const absSize = Math.abs(size);
  if (absSize > 1024) {
    return `${(size / 1024).toFixed(2)} KB`;
  } else if (absSize >= 1) {
    return `${size} B`;
  }
  return '';
}

const originalSize = readFileSync('./dist/oc-client.min.js').length;
function getDiff(compareTo) {
  const newSize = getSize();
  const diff = newSize - compareTo;
  const result = diff > 0 ? 'bigger' : diff < 0 ? 'smaller' : 'same';
  const humanReadable = humanReadableSize(diff);

  return { result, diff, humanReadable };
}

function getText(initial) {
  const { result, humanReadable } = getDiff(originalSize);
  let text = '';
  if (result === 'same') {
    text = 'No changes';
  } else if (result === 'bigger') {
    text = styleText('red', `Current size increased by ${humanReadable}`);
  } else {
    text = styleText('green', `Current size decreased by ${humanReadable}`);
  }

  if (initial) {
    text += `\nTotal reduction: ${getDiff(initial).humanReadable}`;
  }

  return text;
}

async function program(options) {
  if (options.watch) {
    try {
      const watcher = watch(path.join(process.cwd(), 'src/oc-client.js'), {
        signal
      });
      for await (const event of watcher) {
        if (event.eventType === 'change') {
          const text = getText(options.initial);
          console.clear();
          console.log(text);
        }
      }
    } catch (err) {
      if (err.name === 'AbortError') return;
      throw err;
    }
  } else {
    console.log(getText());
  }
}

const options = parseArgs({
  args: process.argv.slice(2),
  options: {
    watch: {
      type: 'boolean',
      default: false,
      short: 'w'
    },
    initial: {
      type: 'string',
      short: 'i'
    }
  }
});

program(options.values);